<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        const p1 = new Promise((resolve,reject)=>{
            try{
                console.log('获取数据a');
                setTimeout(()=>{
                    console.log('a数据获取成功');
                    resolve('我就知道成功了')
                },2000)
            }catch(e){
                reject(e.message)
            }
        })
       const p2 = p1.then((value)=>{
        console.log('成功',value);
         return  new Promise((resolve,reject)=>{
            console.log("开始请求B数据");
            try{
                throw new Error('错啊')
                setTimeout(()=>{
                console.log('获取b成功');
                resolve('bbbb')
                },3000)
            }catch(e){
                reject(e.message)
            }
        })

      





       })
           
       console.log('p2',p2);
    </script>
</body>
</html>